Immunomodulatory Arming Factors-The Current Paradigm for Oncolytic Vectors Relies on Immune Stimulating Molecules.

The dogma of engineering oncolytic viral vectors has shifted from emphasizing the viral lysis of individual cancer cells to the recruitment and coordination of the adaptive immune system to clear the tumor. To accomplish this, researchers have been adding several classes of transgenes to their preferred viral platforms. The most prevalent of these include antibodies and targeting moieties, interleukins and cytokines, and genes which rely on small molecule co-administration for tumor killing. Most current vectors rely exclusively on one of these types of transgenes to elicit the desired immune response to clear tumors, but are not mutually exclusive, with several larger OVs armed with several of these factors. The common theme of emerging armed vectors is to simply initiate or enhance infiltration of effector CD8+ T cells to clear the tumor locally at OV infection sites, and systemically throughout the body where the OV has not infected tumor cells. The precision of oncolytic vectors to target a cell type or tissue remains its key advantage over small-molecule drugs. Unlike chemo- and other drug therapies, viral vectors can be made to specifically infect and grow within tumor cells. This ensures localized expression of the therapeutic transgene to the diseased tissue, thereby limiting systemic toxicity. This review will examine the immunomodulating transgenes of current OVs, describe their general effect on the immune system, and provide the rationale for each vector's use in clearing its targeted tumor.

Thymic Epithelial Tumors: Prognostic Significance and Relationship between Histology and the New TNM Staging System.

BACKGROUND: This study aims to describe the relationship between the new tumor nodes metastasis (TNM) staging and World Health Organization (WHO) classification and to identify how these two variables relate to each other and whether they possess a prognostic value in predicting survival and recurrence of disease. METHODS: Medical records of 54 patients who underwent surgery for thymic epithelial tumors between 1996 and 2015 were reviewed.The histologic type of neoplasm was classified according to the criteria of WHO and staging was evaluated using the new TNM classification system. RESULTS: A significant correlation between the TNM stages and the histological classification was found (p < 0.001). Complete resection is related to both TNM stage and histological grading (p < 0.001). Evaluation of the 5- and 10-year survival curves shows how these are significantly correlated only at the stage (p = 0.03 and = 0.04, respectively). The risk of death at 5 and 10 years for stages III to IV is six and three times higher than in stages I to II, respectively. Regarding the disease-free survival, there is significant correlation with both staging and histology (p = 0.001 and = 0.02, respectively). CONCLUSIONS: There is a significant correlation between the new TNM staging and the histological grade WHO. The ability to implement a complete resection, the overall and disease-free survival is closely related to the thymoma stage. Furthermore, both histotype and stage correlate with disease-free survival. In fact, the least aggressive stages, both WHO and TNM, have a free time out of disease superior to advanced stages.

A Monoclonal Antibody Against ß1 Integrin Inhibits Proliferation and Increases Survival in an Orthotopic Model of High-Grade Meningioma.

BACKGROUND: High-grade meningiomas (HGMs; World Health Organization [WHO] classification grade II and III) have high relapse rates and poor clinical outcomes despite surgery and radiation treatments. No effective medical therapy currently exists for HGMs, and developing novel therapeutic strategies depends on the identification of molecular drivers. In cancer, ß1 integrin enhances malignant characteristics, including proliferation, invasion, and drug resistance. OBJECTIVE: We conducted this study to investigate whether ß1 integrin could be a therapeutic target in HGMs. PATIENTS AND METHODS: Expression of ß1 integrin was examined in gene array datasets, with proteomics of clinical meningioma specimens, and in patient-derived HGM xenografts. Anti-tumor activity of OS2966, a first-in-class humanized antagonizing monoclonal antibody against ß1 integrin, was tested in vitro and in vivo using an orthotopic mouse model of patient-derived malignant meningioma. RESULTS: ß1 integrin was expressed in meningiomas of all WHO grades and two xenografts tested. In vitro, OS2966 suppressed the viability of NF2-deficient MN3 sphere cells and NF2-wild-type IOMM-Lee malignant meningioma cells only when plated on laminin-coated plastic. While OS2966 decreased phosphorylation of ERK1/2 in both MN3 cells and laminin-grown IOMM-Lee cells, OS2966 only affected the phosphorylation of FAK (Tyr397) in MN3, and of Akt (Ser473) in IOMM-Lee cells, respectively, indicating differential pathway inhibition. Systemic administration of OS2966 in mice bearing orthotopic MN3 HGMs inhibited HGM cell proliferation and significantly extended overall survival of the treated mice. CONCLUSIONS: ß1 Integrin may be a therapeutic target in HGMs, and further preclinical and clinical development of OS2966 for HGM therapy is warranted.

Updates on Oncolytic Virus Immunotherapy for Cancers.

The 2018 annual Cambridge Healthtech Institute's International Immuno-Oncology Summit in Boston, MA convened late August, and academic and industry researchers were allowed to debate and discuss oncolytic virology during the virus immunotherapy portion of the conference. The breakthrough agent, TVEC/IMLYGIC, as well as most other oncolytic viruses (OVs) in clinical trials, are demonstrating an immense synergy with T cell checkpoint inhibitors. To this extent, the marriage of T cell checkpoint inhibitors and OV is now vastly accepted, indicating the next phase in OVs is the recruitment of the immune system, and tailoring the immune response toward tumor clearance is a far better strategy than directly lysing the tumor outright with virus. The next field-shaping question for OVs is how to convert a patient's immune response against their tumor. The talks this year focused on whether OVs can cause the emergence of a strong anti-tumor immunity intrinsically or whether vectors, which educate the immune system to detect tumor antigens, were more efficacious. Speakers presented novel transgenes to arm OVs and systems biology approaches to discover the best viral backbones to engineer into vectors. Here we summarize the meeting's keynote talks, thematic principles running through the summit, and current developments in the OV field.

Granular cell tumor of the infundibulum: a systematic review of MR-radiography, pathology, and clinical findings.

INTRODUCTION: Granular cell tumors (GCTs) of the infundibulum are rare in practice and literature, resulting in a lack of evidence-based standard of care. We present two characteristic cases from our institution and perform a systematic review of the existing literature to further elucidate the presentation of this tumor and guide management. METHODS: A systematic literature search was conducted according to PRISMA guidelines, yielding 42 total individual reported GCTs suitable for evaluation. Available clinical presentation, magnetic resonance imaging (MRI) characteristics, pathology, surgical approaches, and outcomes were charted. We measured frequencies of clinical characteristics and performed an outcome comparison of open versus endoscopic surgical treatment. RESULTS: In this pooled dataset, GCT incidence was higher in females than males (3:1). Clinical presentation peaked in the fourth decade with tumor-related symptoms. MRI appearance was characterized by T1 isointensity (50%) and T2 hypointensity or isointensity (52%) with gadolinium contrast enhancement (74%). Histopathology demonstrated positive staining for PAS, PAS-D, S100, CD68, and TTF1. In a simple uncontrolled analysis, patients who underwent endoscopic surgery experienced more symptom improvement (p = 0.006) and lower incidence of new diabetes insipidus postoperatively (p = 0.047) versus patients who underwent open microsurgery. CONCLUSIONS: This first comprehensive review of GCTs of the infundibulum corroborates existing data and adds significant new MR-radiological information to the literature, notably a typical tumor appearance of T1 isointensity, T2 iso- to hypointensity, and gadolinium contrast enhancement. Future prospective studies should be conducted to validate our findings.

Emerging Medical Treatments for Meningioma in the Molecular Era.

Meningiomas are the most common type of primary central nervous system tumors. Approximately, 80% of meningiomas are classified by the World Health Organization (WHO) as grade I, and 20% of these tumors are grade II and III, considered high-grade meningiomas (HGMs). Clinical control of HGMs, as well as meningiomas that relapse after surgery, and radiation therapy is difficult, and novel therapeutic approaches are necessary. However, traditional chemotherapies, interferons, hormonal therapies, and other targeted therapies have so far failed to provide clinical benefit. During the last several years, next generation sequencing has dissected the genetic heterogeneity of meningioma and enriched our knowledge about distinct oncogenic pathways driving different subtypes of meningiomas, opening up a door to new personalized targeted therapies. Molecular classification of meningioma allows a new design of clinical trials that assign patients to corresponding targeted agents based on the tumor genetic subtypes. In this review, we will shed light on emerging medical treatments of meningiomas with a particular focus on the new targets identified with genomic sequencing that have led to clinical trials testing novel compounds. Moreover, we present recent development of patient-derived preclinical models that provide platforms for assessing targeted therapies as well as strategies with novel mechanism of action such as oncolytic viruses.

Multidisciplinary management improves survival at 1 year after surgical treatment for non-small-cell lung cancer: a propensity score-matched study.

OBJECTIVES: The management of patients affected by lung cancer requires the expertise of specialists from different disciplines. Although the advantages of multidisciplinary team discussions seem obvious, there are limited studies evaluating the influence of this approach on postoperative outcomes in non-small-cell lung cancer (NSCLC). The aim of this study is to examine the impact of a multidisciplinary approach on survival of patients undergoing surgery for NSCLC. METHODS: A retrospective analysis was performed on consecutive patients who underwent surgery for NSCLC between January 2008 and December 2015. Data were compared between patients treated before the implementation of a multidisciplinary tumour board (MTB), between 2008 and 2012, and those who received treatment after the implementation of the MTB, between 2012 and 2015. Patients were matched one to one according to the discussion of the MTB and on the basis of a propensity score built using several patient characteristics. A propensity score-matched analysis was performed to compare patient outcomes. RESULTS: A total of 246 patients were treated prior to the initiation of the MTB and 231 patients after the initiation of the MTB. Based on the propensity score, 2 well-matched groups of 170 patients were identified. Patients who were discussed at the MTB were noted to have better outcomes when compared with those who were not discussed at the MTB on different terms including complete staging evaluation, early tumour, node and metastasis (TNM) stages and 1-year survival rate. CONCLUSIONS: Implementation of a multidisciplinary thoracic malignancy conference increased the 1-year survival rate of patients who underwent a surgical resection for NSCLC.

Blockade of transforming growth factor-ß signaling enhances oncolytic herpes simplex virus efficacy in patient-derived recurrent glioblastoma models.

Despite the current standard of multimodal management, glioblastoma (GBM) inevitably recurs and effective therapy is not available for recurrent disease. A subset of tumor cells with stem-like properties, termed GBM stem-like cells (GSCs), are considered to play a role in tumor relapse. Although oncolytic herpes simplex virus (oHSV) is a promising therapeutic for GBM, its efficacy against recurrent GBM is incompletely characterized. Transforming growth factor beta (TGF-ß) plays vital roles in maintaining GSC stemness and GBM pathogenesis. We hypothesized that oHSV and TGF-ß inhibitors would synergistically exert antitumor effects for recurrent GBM. Here we established a panel of patient-derived recurrent tumor models from GBMs that relapsed after postsurgical radiation and chemotherapy, based on GSC-enriched tumor sphere cultures. These GSCs are resistant to the standard-of-care temozolomide but susceptible to oHSVs G47Δ and MG18L. Inhibition of TGF-ß receptor kinase with selective targeted small molecules reduced clonogenic sphere formation in all tested recurrent GSCs. The combination of oHSV and TGF-ßR inhibitor was synergistic in killing recurrent GSCs through, in part, an inhibitor-induced JNK-MAPK blockade and increase in oHSV replication. In vivo, systemic treatment with TGF-ßR inhibitor greatly enhanced the antitumor effects of single intratumoral oHSV injections, resulting in cures in 60% of mice bearing orthotopic recurrent GBM. These results reveal a novel synergistic interaction of oHSV therapy and TGF-ß signaling blockade, and warrant further investigations aimed at clinical translation of this combination strategy for GBM patients.

AS1411-Induced Growth Inhibition of Glioma Cells by Up-Regulation of p53 and Down-Regulation of Bcl-2 and Akt1 via Nucleolin.

AS1411 binds nucleolin (NCL) and is the first oligodeoxynucleotide aptamer to reach phase I and II clinical trials for the treatment of several cancers. However, the mechanisms by which AS1411 targets and kills glioma cells and tissues remain unclear. Here we report that AS1411 induces cell apoptosis and cycle arrest, and inhibits cell viability by up-regulation of p53 and down-regulation of Bcl-2 and Akt1 in human glioma cells. NCL was overexpressed in both nucleus and cytoplasm in human glioma U87, U251 and SHG44 cells compared to normal human astrocytes (NHA). AS1411 bound NCL and inhibited the proliferation of glioma cells but not NHA, which was accompanied with up-regulation of p53 and down-regulation of Bcl-2 and Akt1. Moreover, AS1411 treatment resulted in the G2/M cell cycle arrest in glioma cells, which was however abolished by overexpression of NCL. Further, AS1411 induced cell apoptosis, which was prevented by silencing of p53 and overexpression of Bcl-2. In addition, AS1411 inhibited the migration and invasion of glioma cells in an Akt1-dependent manner. Importantly, AS1411 inhibited the growth of glioma xenograft and prolonged the survival time of glioma tumor-bearing mice. These results revealed a promising treatment of glioma by oligodeoxynucleotide aptamer.

A new patient-derived orthotopic malignant meningioma model treated with oncolytic herpes simplex virus.

BACKGROUND: Higher-grade meningiomas (HGMs; World Health Organization grades II and III) pose a clinical problem due to high recurrence rates and the absence of effective therapy. Preclinical development of novel therapeutics requires a disease model that recapitulates the genotype and phenotype of patient HGM. Oncolytic herpes simplex virus (oHSV) has shown efficacy and safety in cancers in preclinical and clinical studies, but its utility for HGM has not been well characterized. METHODS: Tumorsphere cultures and serial orthotopic xenografting in immunodeficient mice were used to establish a patient-derived HGM model. The model was pathologically and molecularly characterized by immunohistochemistry, western blot, and genomic DNA sequencing and compared with the patient tumor. Anti-HGM effects of oHSV G47Δ were assessed using cell viability and virus replication assays in vitro and animal survival analysis following intralesional injections of G47Δ. RESULTS: We established a serially transplantable orthotopic malignant meningioma model, MN3, which was lethal within 3 months after tumorsphere implantation. MN3 xenografts exhibited the pathological hallmarks of malignant meningioma such as high Ki67 and vimentin expression. Both the patient tumor and xenografts were negative for neurofibromin 2 (merlin) and had the identical NF2 mutation. Oncolytic HSV G47Δ efficiently spread and killed MN3 cells, as well as other patient-derived HGM lines in vitro. Treatment with G47Δ significantly extended the survival of mice bearing subdural MN3 tumors. CONCLUSIONS: We established a new patient-derived meningioma model that will enable the study of targeted therapeutic approaches for HGM. Based on these studies, it is reasonable to consider a clinical trial of G47Δ for HGM.

Extreme Vulnerability of IDH1 Mutant Cancers to NAD+ Depletion.

Heterozygous mutation of IDH1 in cancers modifies IDH1 enzymatic activity, reprogramming metabolite flux and markedly elevating 2-hydroxyglutarate (2-HG). Here, we found that 2-HG depletion did not inhibit growth of several IDH1 mutant solid cancer types. To identify other metabolic therapeutic targets, we systematically profiled metabolites in endogenous IDH1 mutant cancer cells after mutant IDH1 inhibition and discovered a profound vulnerability to depletion of the coenzyme NAD+. Mutant IDH1 lowered NAD+ levels by downregulating the NAD+ salvage pathway enzyme nicotinate phosphoribosyltransferase (Naprt1), sensitizing to NAD+ depletion via concomitant nicotinamide phosphoribosyltransferase (NAMPT) inhibition. NAD+ depletion activated the intracellular energy sensor AMPK, triggered autophagy, and resulted in cytotoxicity. Thus, we identify NAD+ depletion as a metabolic susceptibility of IDH1 mutant cancers.

Targeting Hypoxia-Inducible Factor 1α in a New Orthotopic Model of Glioblastoma Recapitulating the Hypoxic Tumor Microenvironment.

Tissue hypoxia and necrosis represent pathophysiologic and histologic hallmarks of glioblastoma (GBM). Although hypoxia inducible factor 1α (HIF-1α) plays crucial roles in the malignant phenotypes of GBM, developing HIF-1α-targeted agents has been hampered by the lack of a suitable preclinical model that recapitulates the complex biology of clinical GBM. We present a new GBM model, MGG123, which was established from a recurrent human GBM. Orthotopic xenografting of stem-like MGG123 cells reproducibly generated lethal tumors that were characterized by foci of palisading necrosis, hypervascularity, and robust stem cell marker expression. Perinecrotic neoplastic cells distinctively express HIF-1α and are proliferative in both xenografts and the patient tissue. The xenografts contain scattered hypoxic foci that were consistently greater than 50 µm distant from blood vessels, indicating intratumoral heterogeneity of oxygenation. Hypoxia enhanced HIF-1α expression in cultured MGG123 cells, which was abrogated by the HIF-1α inhibitors digoxin or ouabain. In vivo, treatment of orthotopic MGG123 xenografts with digoxin decreased HIF-1α expression, vascular endothelial growth factor mRNA levels, and CD34-positive vasculature within the tumors, and extended survival of mice bearing the aggressive MGG123 GBM. This preclinical tumor model faithfully recapitulates the GBM-relevant hypoxic microenvironment and stemness and is a suitable platform for studying disease biology and developing hypoxia-targeted agents.

Role of ventriculoperitoneal shunting in patients with neoplasms of the central nervous system: An analysis of 59 cases.

Approximately 1-5% of patients with cerebral metastasis and ~40% of patients with primary brain tumors suffer from hydrocephalus. These patients often exhibit a poor prognosis. The aim of the present study was to reassess the validity of ventriculoperitoneal shunting (VPS) with the assistance of the general surgeon in oncological patients. A total of 59 patients underwent first-time VPS at the Beth Israel Deaconess Medical Center (Boston, USA) between 2004 and 2012; 40 patients had hydrocephalus from brain metastasis and 19 from primary tumors. The analyzed independent variables included demographics, body mass index, past medical history, clinical presentation, indication for surgery, Karnofsky performance status (KPS) score and surgical technique; the dependent variables were postoperative symptoms and occurrence, cause and time of shunt failure. The outcomes were analyzed with the t-test and Kaplan-Meier estimates for shunt survival. The mean age of the patients was 57.2 years and the mean operative time was 50.4 min. Symptomatic palliation was achieved in 93% of the cases; patients with severe symptoms, such as debilitating headaches, nausea and vomiting, benefited significantly from VPS. The mean follow-up time was 6.3 months; complications occurred in only 7 patients (11.8%) during follow-up: 2 in the proximal shunt (1 infection and 1 obstruction), both requiring revision, 1 infection in the distal catheter requiring shunt removal, 2 cases of intracerebral bleeding that were monitored with computed tomography scans, 1 wound infection treated with antibiotics and 1 valve complication that required temporary revision. The initial and 3-month KPS scores were 65±16.4 and 75±16.0, respectively. The mean overall shunt survival was 6.4 months (range, 1.0 day-76.0 months) from the placement of the VP shunt. At 3 months after VPS, 93.5% of the patients remained alive with functioning shunts and at 1 year 87% of the shunts were still functioning. In conclusion, VPS remains a valid option for cancer patients with low KPS, as it improves the quality of life in such patients, even in the setting of previous infection, hemorrhage, or leptomeningeal disease, since shunt patency outlasts the overall survival of nearly all patients.

Ventriculoperitoneal shunting: Laparoscopically assisted versus conventional open surgical approaches.

OBJECTIVES: Ventriculoperitoneal shunting (VPS) is a mainstay of hydrocephalus therapy, but carries a significant risk of device malfunctioning. This study aims to compare the outcomes of laparoscopic ventriculoperitoneal shunting versus open ventriculoperitoneal shunting (OVPS) VPS-placement and reviews our findings in the pertinent context of the literature from 1993 to 2012. MATERIALS AND METHODS: Between 2003 and 2012, a total of 232 patients underwent first time VPS placement at Beth Israel Deaconess Medical Center. Of those, 155 were laparoscopically guided and 77 were done conventionally. We analyzed independent variables (age, gender, medical history, clinical presentation, indication for surgery and surgical technique) and dependent variables (operative time, post-operative complications, length of stay in the hospital) and occurrence of shunt failure. RESULTS: Mean operative time was 43.7 min (18.0-102.0) in the laparoscopic group versus 63.0 min (30.0-151.0) in the open group, (P < 0.05). Length of stay was similar, 5 days in the laparoscopic and in the open group, (P = 0.945). The incidence of shunt failure during the entire follow-up period was not statistically different between the two groups, occurring in 14.1% in the laparoscopic group and 16.9% in the open group, (P = 0.601). Kaplan-Meier analysis demonstrated no difference in shunt survival between the two groups (P = 0.868), with functionality in 85% at 6-months and 78.5% at 1-year. CONCLUSION: According to our study, LVPS-placement results compare similarly to OVPS placement in most aspects. Since laparoscopic placement is not routinely indicated, we suggest a prospective study to assess its value as an alternate technique especially suitable in obese patients and patients with previous abdominal operations.

Shunting for hydrocephalus: analysis of techniques and failure patterns.

BACKGROUND: Hydrocephalus is characterized by ventricular dilatation because of progressive accumulation of cerebrospinal fluid. Normal pressure hydrocephalus (NPH) affects a subset of patients representing a reversible clinical triad of gait disturbance, urinary incontinence, and dementia with normal cerebrospinal fluid pressure and composition. Various shunting procedures have been used for treatment, but techniques and outcomes remain under debate. The objective of this study was to evaluate the clinical outcomes of 232 patients with and without NPH after the first-time Ventriculoperitoneal shunt placement and assessed patterns of failure between December 2004 and December 2012. RESULTS: Mean age was 54.7 y in non-NPH and 71.9 y in NPH patients. We used open technique in 34.3% and laparoscopic technique in 65.7% of NPH patients and 32.7% and 67.3% of the non-NPH patients, respectively. A total of 36 of 232 patients displayed shunt failure, 16.4% in NPH and 15.2% in non-NPH patients. Twenty-three of 155 patients failed after laparoscopic and 13 of 77 failed after open placement. Proximal shunt failure was more frequent in the non-NPH cohort. Distal failures accounted for 13 of 232 cases, and the difference between laparoscopic (six of 155) and open failures (seven of 77) was profound, but not between NPH- and non-NPH patients. CONCLUSIONS: Shunt failures are related to the placement method. Non-NPH patients showed more proximal failures. NPH patients showed fewer proximal failures. Less distal failures were observed after laparoscopic ventriculoperitoneal shunt placement without significant differences between NPH and non-NPH patients. Beyond this, laparoscopic surgery carries distinct advantages such as shorter operating room times and hospital stays, which should translate into less use of pain medications, earlier mobilization, and a lower incidence of ileus.